Olfactory dysfunction increases susceptibility to the hazards of fire, ingestion of spoiled food and exposure to chemical toxins, and it can lead to nutritional problems and reduce the quality of life. These risks are heightened in the workplace. Yet, more than 10% of the U.S. workforce approximately 14 million people) has daily occupational exposure to chemicals or particulates and as many as 40% of these individuals report symptoms of chronic nasal inflammation or rhinitis that are known precursors of olfactory loss. Despite this, the evaluation of olfactory function in susceptible occupational cohorts is rarely performed and consequently, little is known about the prevalence of and mechanisms underlying chemical-induced olfactory dysfunction in humans. Because the mechanisms of olfactory dysfunction secondary to chemical exposure are likely to be multi-factorial, including anatomical changes (e.g., congestion, polyposis), changes in mucociliary transport and direct effects of inflammatory mediators on the olfactory neuroepithelium, this proposal takes a multi-pronged approach to provide a comprehensive, longitudinal clinical evaluation of the chemosensory function, nasal inflammatory processes and airflow patterns among individuals with prospective and ongoing chemical exposures. Using techniques developed in the current funding period and advances in our ability to numerically model olfactory transport and deposition in individualized patient models, we propose to study three cohorts with exposure to putative olfactory toxicants. We will evaluate chemosensory function at multiple timepoints before, during and after exposure (Aim 1) and develop profiles of the physical and biochemical inflammatory changes that occur in the noses of exposed individuals (Aim 2). In addition to the clinical cohorts, we will develop a database of olfactory function based on job type by screening individuals with chemical exposures who are referred to the University of Pennsylvania Occupational Medicine Clinic. In Aim 3, we will use our computational model to evaluate the impact of inflammatory changes in nasal airflow which are responsible for olfactory toss secondary to chemical exposures and nasal-sinus disease (in Project 1). Results of these studies will provide an important resource for predicting and mitigating the effects from occupational chemical exposure on chemosensory function. These findings will inform policies and practices to protect the sensory function and health of both young adults and the elderly, for whom chemical exposure appears to increase the severity of age-related sensory declines. Through evaluation of a wide range of relevant characteristics, the outcome will also support reasoned predictions about risk factors that may mitigate or exacerbate the functional chemosensory impact of inflammatory processes, which are prevalent in the general population from a variety of chronic health and exposure conditions.